52张扑克中任取4张,仅2张花色相同的概率.
问题描述：
52张扑克中任取4张,仅2张花色相同的概率.
答
(C(4,1)*C(13,3)*39+C(4,2)*C(13,2)*C(13,2))/C(52,4)
=(4*286*39+6*78*78)/270725
=(44616+36504)/270725
=1248/4165
≈0.2996
答
C(4,2)C(13,1)C(39,1)C(26,1)/C(52,4)=0.292
答
C(4,2)C(4,1)C(13,1)C(3,2)C(13,1)C(13,1)/C(52,4)=0.584